Means for refinishing small grinding-wheels



A. F. CRAMPTON.

MEANS FOR REFINISHING SMALL GRINDING WHEELS. APPLICATION FILED APR.18,1921.

1 $393,667. Patented Oct. 11, 1921 Fig.1.

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ARTHUR F. CRAMPTON, WEST HARTFORD, CONNECTICUT.

MEANS FOR REFIIIISI-IING SMALL'G RINDIN G-WHEELS. I

Specification of Letters Iatent.

Patented Oct. 11, 1921.

Application filed April 18, 1921. Serial No. 462,286.

To all whom it may concern Be it known that I, ARTHUR F. CRAMPTON, acitizen of the United States, residing at West Hartford, in the countyof Hartford and State of Connecticut, have invented certain new anduseful Improvements'in Means for Refinishing Small Grinding-Wheels, ofwhich the following is a specification.

, This invention relates to a holder and tool therefor, and especiallyto a holder and diamond pointed tool for truing and resurfacing smallgrinding wheels of the type employed by dentists in performing much ofthe work incidental to filling and other wise repairing teeth. Suchwheels are held for rotation in the handle provided at the end of theflexible shaft of a dental engine and applied to their work by the handof an operator. The manner of applying the tools to their work and thecharacter of the substances to which they are applied cause them toquite rapidly wear out of round or become glazed and unfit for use.However, a true cylindrical form may again be imparted to the wheels andthe grinding sur face renewed by means of a diamond pointed turningtool.

One object of my invention is thevprovision in a device for renewing theform and surface of small grinding wheels, of a construction of novelform and arrangement including features of adjustment, wherebyconvenience, efiicient operation and low cost of manufacture areassured. Another object of the invention is the provision of a diamondtool and holder therefor suitable for support upon the instrument standof a dental operator and adapted to cooperate with thenormal holding anddriving means of a dental grinding wheel in a process of dressing thework engaging surface of the latter. To this end the invention consistsin the simple construction andnovel arrangement of parts set forth inthe following detailed description and illustrated in the accompanyingdrawings, in which,-

Figure 1, is a View in elevation of a tool holder and tool constructedin accordance with my invention. In this view there is also shown indot-and-dash lines a small emery wheel in a certain position relative tothe diamond point which will be hereinafter more fully explained.

Fig. 2, is a view in elevation ofthe tool holder as it would be seenlooking in the direction of the arrow in Fig. 1.

Fig. 3, is a sectional view on line 33 of F 1g. 2, it also shows agrinding wheel supported by the work rest.

Flg. 4:, is a sectional view on line H of Fig. 3, and,

Fig. 5, is a sectional view on line 55 of Fig. 3.

Referring to the drawings, the numeral 1, designates a standard whichcomprises, preferably in integral form, a base 2, body portion 3, andthe work rest 4:. The base, as shown is circular, the body portioncylindrical and the work rest is an arm extending from the body portionand terminating in a head 5, of V-block form. ,A diamond tool suitablefor use in the holder is best shown in Fig. 3. It consists of a rod6,-with a diamond point 7, set in one end, and at the opposite endprovided with a slightly enlarged head 8. This tool is designed to beheld in the body portion of the standard with the diamond pointed endprojecting therefrom for engagement with a grinding wheel as 9,comprising the work, the shank or arbor 10, of which is supported andguided by the work rest 5, at right angles to the longitudinal axis ofthe tool. For different characters of work, adjustment of the diamondtool is' required and means for permitting and effecting suchadjustment, together with means for rigidly securing the tool inadjusted relation to the work will now be described.

To receive the diamond tool there is extended through the standard fromthe hol-' low base thereof, a bore 11, countersunk at 12, to form theshoulder 13, and threaded to receive the adjusting screw 14;, the latterbeing bored out at 15, to receive and house a light compression spring16, said spring also engaging the adjacent end of the diamond tool andtending to move the tool in a direction to engage its head 8, with theshoulder 13. l/Vith the diamond tool thus limited in its outwardmovement by the shoulder 13, it assumes a position with the diamondpoint substantially coincident with the axis defined by a tool arborsupported by the work rest, or in other words, the diamond point isslightly beyond the extreme limit of adjustment required for work ofminimum diameter. For a given diameter of work the diamond tool may bebrought to the required position by placing the grinding wheel to beoperated upon in contact with the diamond point and then to gether withthe grinding wheel, moving the tool against the pressure of spring 16,until the grinding wheel arbor comes into engagement and suitablealinement with the work rest. Such position of the tool is then securedby clamping means which may be of any suitable form,--that shown isassociated with the body portion of the standard, which to receive theclamping member is providedwith a hole 17, transversely extended andintersecting the tool receiving bore 11. The hole 17 is counterbored at18, to receive the hub of a knurled headed nut 19, which is threadedupon the clamping member or bolt 20, the latter having a transverseopening 21, to register with the bore 11, so that the tool 6, may extendthrough it and engage the bore '11, on both sides of the bolt, therebyproviding a construction with ample and advantageously distributedclamping surfaces. The clamping action of the bolt is controlled by thenut 19, and it will be clear that the arrangement just describedprovides means for quickly securing the tool in an adjusted position orfor quickly releasing it to permit of changing its adjustment.

As hereinbefore intimated the tension of spring 16, is preferably justsufficient to overcome the weight of the diamond tool and move it whenreleased to its outermost position. The degree of tension necessary forthis purpose may be secured by manipulating the nut 14:.

, In the use of my improved device the manner of proceeding may be asfollows release the nut 19, to permit the diamond tool to move to theextreme limit of its adjustment toward an axis defined by the work rest(seedot-and-dash lines, Fig. 1) then with the grinding wheel to beresurfaced secured in the chuck or handle of a dental engine but withthe motive power turned ofi, apply the periphery of the grinddiamondpoint and, maining wheel to th taining this relatlon, move the twoagainst the pressure of spring 16, until the grinding wheel arborengages with the work rest 5, in alined relation thereto. This will givean adjustment closely approximating that best suited for the turningoperation,should a slightchange be desired it may readily be obtained bymaintaining contact of the grinding wheel arborwith the work rest andslightly tilting the arborfrom the alinement to be derived from the workrest during the, turning operation. With the desired adjustmenteffected, after the manner set forth, it is secured against displacementby tightening the clamping nut 19. The power for rotating the grindingwheel is then turned on, and with the wheel rotating at a high rate ofspeed it is moved back and forth across the diamond point in analinement defined by the work rest.

Having thus described my invention, what Iclaimis,-- V 1. A device ofthe class described including in combination, a standard having a toolreceiving bore, a work rest associated with the standard, means foryieldingly moving a tool in the bore toward an axis defined by the workrest, and means for clamping the tool in the standard.

2. A device of theclass described including in combination, a standardhaving a tool receiving bore, awork rest associated with the standard, atool movable longitudinally of the bore toward and from an axis definedby the work rest, and means for clamping the tool against movement.

3. A device of the class described including in combination, a standardhaving a counterbored tool receiving bore, a work rest associated withthe standard, a tool extending through the bore into the counterbore, aspring within the counterbore for moving the tool toward an axis definedby the work rest, stop means within the counterbore for limitingmovement of the tool imparted by the spring, and means for clampingthe'tool against movement.

at. A device of the class described including in combination a standardhaving a hollow base and a body portion with a tool receiving boreextending therethrough from the hollow base, a work rest associated withthe body portion, a tool extending into the bore, a spring in the borefor moving the tool toward an axis defined by the work.

rest, means within the base for adjusting the tension of said spring,and means for clamping the tool against movement.

In testimony whereof I aifix my signature.

ARTHUR F. CRAMPTON

